The arrangement of satellite sequences in DNA of the higher organism remains an allusive mystery. The arrangement of these sequences in Drosophila melanogaster will be determined by 1) The isolation of DNA of Drosophila melanogaster with molecular weight greater than 10 to the 10th power daltons so that the length of each satellite region/chromosome can be measured. 2) The mapping of satellites in Drosophila by the methods of genetics combined with physical isolation techniques. 3) The fragmentation of Drosophila DNA with restriction enzymes to provide independent molecular evidence for the mapping observed by the methods of genetics.